new Column(
crossAxisAlignment: CrossAxisAlignment.start,
mainAxisSize: MainAxisSize.min,
children:
[
new Text(
'We move under cover and we move as one'),
new Text(
'Through the night, we have one shot to live another day'),
new Text(
'We cannot let a stray gunshot give us away'),
new Text(
'We will fight up close, seize the moment and stay in it'),
new Text(
'It’s either that or meet the business end of a bayonet'),
new Text(
'The code word is ‘Rochambeau,’ dig me?'),
new Text(
'Rochambeau!', style: DefaultTextStyle.of(context).style.apply(fontSizeFactor:
2.0)), ], )

The problem, as described in the details that accompany that exception, is that using Flexible or Expanded means that the remaining space after laying out all the other children must be shared equally, but if the incoming vertical constraints are unbounded, there is infinite remaining space.

Divide the remaining vertical space among the children with non-zero flex factors (e.g., those that are Expanded) according to their flex factor. For example, a child with a flex factor of 2.0 will receive twice the amount of vertical space as a child with a flex factor of 1.0.

Layout each of the remaining children with the same horizontal constraints as in step 1, but instead of using unbounded vertical constraints, use vertical constraints based on the amount of space allocated in step 2. Children with Flexible.fit properties that are FlexFit.tight are given tight constraints (i.e., forced to fill the allocated space), and children with Flexible.fit properties that are FlexFit.loose are given loose constraints (i.e., not forced to fill the allocated space).